This includes clay bricks, concrete blocks, ceramic tiles, stone slabs and setts, cobbles and slate pitching, and precast concrete slabs. Points to remember when designing for unit paving include the pattern and its direction. Typically, continuous joints should be laid across a path rather than along it, because irregularities in a continuous joint alignment will show up more readily. Laying the continuous joint across a path or route also allows for the use of stone slabs of differing length and constant width, which is much more economical and less wasteful than attempting absolute uniformity of dimensions. Remember: stone is a finite resource.